Electronic apparatus and control method thereof

ABSTRACT

Disclosed is an electronic apparatus. The electronic apparatus obtains a first character string comprising a previously defined character from first user utterance; recognizes a second character string, which is edited from the first character string based on a first edition command, as an input character, based on the first user utterance comprising the first edition command following the first character string; and performs edition with regard to the second character string based on second edition command, based on second user utterance comprising the second edition command without the first edition command.

CROSS-REFERENCE TO RELATED THE APPLICATION

This application is based on and claims priority under 35 U.S.C. § 119to Korean Patent Application No. 10-2019-0172725 filed on Dec. 23, 2019in the Korean Intellectual Property Office, the disclosure of which isincorporated by reference herein in its entirety.

BACKGROUND Field

The disclosure relates to an electronic apparatus and a control methodthereof, and more particularly to an electronic apparatus, in which acharacter string is edited according to a user's utterance, and a methodof controlling the same.

Description of the Related Art

A user can control various functions of an electronic apparatus based ona voice recognition function. For example, in a case of a television(TV), when a user utters a channel number of a desired channel to watch,the TV recognizes the channel number and displays an image correspondingto the recognized channel number. Besides, a user may input a characterbased on the voice recognition function. For example, in a case whereuser account information, e.g. a password is input to the TV, when auser utters characters such as alphabets, digits, symbols, etc.contained in the password in units of individual letters, the TVrecognizes the characters uttered in units of individual letters andreceives the recognized characters as the password.

In a case where a wrong character is entered while the characters areinput through the voice recognition function, when a user utters anedition command to edit the wrong character, the TV recognizes theedition command and edit the wrong character upon the recognized editioncommand. However, there are limits to the kind and number ofrecognizable edition commands, and the edition function based on theedition command is also simple. Therefore, utilization of the editionfunction is low, and convenience in using a character input based on thevoice recognition function is also low.

SUMMARY

An aspect of the disclosure is to provide an electronic apparatus and acontrol method thereof, in which more various and extensive editioncommands can be issued for a wrong character input during a characterinput using a voice recognition function, thereby improving utilizationof an edition function based on voice recognition.

According to an embodiment of the disclosure, there is provided anelectronic apparatus including: a processor configured to: obtain afirst character string comprising a previously defined character fromfirst user utterance; recognize a second character string, which isedited from the first character string based on a first edition command,as an input character, based on the first user utterance comprising thefirst edition command following the first character string; and performedition with regard to the second character string based on secondedition command, based on second user utterance comprising the secondedition command without the first edition command.

The first edition command comprises a command issued to delete acharacter contained in the first character string.

Commands recognizable as the second edition command are more thancommands recognizable as the first edition command.

The processor is configured to: recognize the second edition commandbased on a voice recognition engine; and recognize a command forcontrolling the electronic apparatus based on the voice recognitionengine.

The processor is configured to recognize the first character string andthe first edition command with regard to the first user utterancereceived in a character input mode activated based on a previouslydefined event.

The processor is configured to identify whether the second editioncommand is contained in the second user utterance received while thecharacter input mode is being activated.

The processor is configured to: activate the character input mode basedon a first event; and terminate the activation of the character inputmode based on a second event.

The processor is configured to activate the character input mode basedon a received user input.

Based on the second user utterance comprising a third character stringcomprising the previously defined character, the processor is configuredto perform the edition (i.e. edit) with regard to the second characterstring based on the second edition command without recognizing the thirdcharacter string as the input character.

The processor is configured to control the display to display the secondcharacter string recognized as the input character but not to displaythe third character string not recognized as the input character.

The processor is configured to: obtain a fourth character stringcomprising the previously defined character from third user utterance;and recognize the fourth character string as the input character, basedon the third user utterance comprising no first edition commandfollowing the fourth character string.

The processor is configured not to identify whether the second userutterance comprises the second edition command, based on the first userutterance comprising the first edition command.

According to another embodiment of the disclosure, there is provided amethod of controlling an electronic apparatus, comprising: obtaining afirst character string comprising a previously defined character fromfirst user utterance; recognizing a second character string, which isedited from the first character string based on a first edition command,as an input character, based on the first user utterance comprising thefirst edition command following the first character string; andperforming edition with regard to the second character string based onsecond edition command, based on second user utterance comprising thesecond edition command without the first edition command.

The first edition command comprises a command issued to delete acharacter contained in the first character string.

Commands recognizable as the second edition command are more thancommands recognizable as the first edition command.

The performing the edition comprises: recognizing the second editioncommand based on a voice recognition engine; and recognizing a commandfor controlling the electronic apparatus based on the voice recognitionengine.

The obtaining the first character string comprises recognizing the firstcharacter string and the first edition command with regard to the firstuser utterance received in a character input mode activated based on apreviously defined event.

The performing the edition comprises identifying whether the secondedition command is contained in the second user utterance received whilethe character input mode is being activated.

Further comprising: activating the character input mode based on a firstevent; and terminating the activation of the character input mode basedon a second event.

According to another embodiment of the disclosure, there is provided arecording medium stored with a computer program comprising a code forperforming a control method of an electronic apparatus as a computerreadable code, the control method comprising: obtaining a firstcharacter string comprising a previously defined character from firstuser utterance; recognizing a second character string, which is editedfrom the first character string based on a first edition command, as aninput character, based on the first user utterance comprising the firstedition command following the first character string; and performingedition with regard to the second character string based on secondedition command, based on second user utterance comprising the secondedition command without the first edition command.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects will become apparent and more readilyappreciated from the following description of embodiments, taken inconjunction with the accompanying drawings, in which:

FIG. 1 illustrates an electronic apparatus according to an embodiment ofthe disclosure;

FIG. 2 shows an example of a configuration of the electronic apparatusof FIG. 1;

FIG. 3 shows an example of a control method of the electronic apparatusof FIG. 1;

FIG. 4 illustrates a configuration of an electronic apparatus accordingto an embodiment of the disclosure;

FIG. 5 shows another example of the control method of the electronicapparatus shown in FIGS. 3 and 4;

FIG. 6 shows an example of a user input for activating a character inputmode in connection with an operation S51 in FIG. 5;

FIG. 7 shows an example of performing a first intention analysis duringthe activation of the character input mode in connection with anoperation S52 in FIG. 5;

FIG. 8 shows an example of a control method of inputting a character inconnection with operations S32 and S33 in FIG. 3;

FIG. 9 shows an example of editing a character string based on thecontrol method of FIG. 8;

FIG. 10 shows an example of a control method of inputting a character inconnection with the operations S32 and S33 in FIG. 3;

FIG. 11 shows an example of editing a character string based on thecontrol method of FIG. 10;

FIG. 12 shows an example of a control method of inputting a character inconnection with the operations S32 and S33 in FIG. 3;

FIG. 13 shows an example of editing a character string based on thecontrol method of FIG. 12;

FIG. 14 shows an example of a control method of inputting a character inconnection with the operations S32 and S33 in FIG. 3;

FIG. 15 shows an example of editing a character string based on thecontrol method of FIG. 14; and

FIG. 16 shows an example of a first voice recognition engine and asecond voice recognition engine in connection with the operations S32and S33 in FIG. 3.

DETAILED DESCRIPTION OF EMBODIMENTS

Below, embodiments of the disclosure will be described in detail withreference to accompanying drawings. In the description of the followingembodiments, elements illustrated in the accompanying drawings will bereferenced, and like numerals or symbols set forth in the drawings referto like elements having substantially the same operations. In thedisclosure, at least one among a plurality of elements refers to notonly all the plurality of elements but also both each one of theplurality of elements excluding the other elements and a combinationthereof.

FIG. 1 illustrates an electronic apparatus according to an embodiment ofthe disclosure. As shown in FIG. 1, the electronic apparatus 1 mayinclude not only an image displaying apparatus such as a television(TV), a tablet computer, a portable media player, a wearable device, avideo wall, an electronic frame, etc., but also various kinds ofapparatuses without a display, for example, an image processingapparatus such as a set-top box, etc.; a home appliance such as arefrigerator, a washing machine, etc.; and an information processingapparatus such as a computer, etc. Further, the electronic apparatus 1may be embodied by an artificial intelligence (AI) loudspeaker, an AIrobot, or the like having an AI function. The kinds of electronicapparatus 1 are not limited to these examples, but it will be assumedfor convenience of description that the electronic apparatus 1 isembodied by the TV.

The electronic apparatus 1 may include a microphone 17. The electronicapparatus 1 may receive a voice signal of user utterance 5 uttered by auser 4 through the microphone 17. The microphone 17 may be provided in amain body of the electronic apparatus 1, but not limited thereto.Alternatively, the microphone may be provided in a remote controller 2,a smartphone, etc. separated from the main body, etc. In this case, theelectronic apparatus 1 may receive a voice signal received in themicrophone 17 of the remote controller, the smartphone, etc.

The electronic apparatus 1 may perform a voice recognition function.When receiving the user utterance 5 from the user 4, the electronicapparatus 1 may obtain a voice signal from the user utterance 5, apply avoice recognition process to the obtained voice signal and perform anoperation corresponding to a recognition result based on the voicerecognition process. The voice recognition process includes aspeech-to-text (STT) process for converting a voice signal into textdata, and a commend identifying and following process for identifying acommand based on the text data and performing an operation specified bythe identified command. For example, when the user utterance 5 is“volume up”, the electronic apparatus 1 obtains text data based on thevoice signal of the user utterance 5, identifies the command specifiedby the obtained text data, and turns up the volume of the electronicapparatus 1 based on the identified command.

Both the STT process and the command identifying and following processof the voice recognition process may be fulfilled in the electronicapparatus 1. However, this case makes the electronic apparatus 1 besubjected to relatively high system load and relatively high storagecapacity. Therefore, at least a part of the process may be performed byat least one server 3 connecting and communicating with the electronicapparatus 1 through a network. For example, the at least one server 3may perform the STT process, and the electronic apparatus 1 may performthe command identifying and following process.

Alternatively, the at least one server 3 may perform both the STTprocess and the command identifying and following process, and theelectronic apparatus 1 may receive only results from the at least oneserver 3. For example, the electronic apparatus 1 may receive text dataconverted by a first server 31, which performs the STT process, of theat least one server 3, transmit the received text data to a secondserver 32 or a third server 33 which performs the command identifyingand following process, and receive results from the second server 32 orthe third server 33. However, for convenience of description, thedescription will be made on the assumption that the electronic apparatus1 performs both the STT process and the command identifying andfollowing process.

The electronic apparatus 1 may include at least one voice recognitionmodel to perform the STT process. The voice recognition model refers toa hardware/software component used in a voice recognition process for avoice signal based on the user utterance 5. The voice recognition modelmay include a voice recognition program, a voice recognition engine,etc., and the voice recognition program may be given in the form of anapplication. The voice recognition model may for example include ahidden Markov Model (HMM), an acoustic model achieved by applyingstatistical modeling based on dynamic time warping (DTW) or the likealgorithm to an uttered voice, a language model achieved by collecting acorpus (i.e. a collection of texts given in the forms to be handled,processed and analyzed by a computer for language research), etc.However, the voice recognition model is not limited to this example, butmay include a language model in which N words after the current word areused in analyzing utterance intention like concept of a bigram and atrigram.

The electronic apparatus 1 may receive a character through the voicerecognition function. For example, when a password input screen isdisplayed to receive a password for logging on to a specific service andthe user 4 utters the password in units of individual letters, theelectronic apparatus 1 recognizes the password uttered in units ofindividual letters and makes the recognized password be input to thepassword input screen.

The electronic apparatus 1 may edit a character previously input throughthe voice recognition function. When a wrong password is input to thepassword input screen and the user 4 utters a sound for editing thepreviously input password, the electronic apparatus 1 may edit thepreviously input password based on the utterance for the edition.

FIG. 2 illustrates a configuration of the electronic apparatus ofFIG. 1. As shown in FIG. 2, the configuration of the electronicapparatus 1 will be described below in detail with reference to FIG. 2.In this embodiment, it will be described that the electronic apparatus 1is a TV. However, the electronic apparatus 1 may be embodied by variouskinds of apparatuses, and therefore the electronic apparatus 1 is notlimited to this embodiment. The electronic apparatus 1 may not beembodied by the TV or the like display apparatus, and the electronicapparatus 1 in this case may not include the display 14 and the likeelements for displaying an image. For example, when the electronicapparatus 1 is embodied by a set-top box, the electronic apparatus 1 mayoutput an image signal to an external TV through an interface 11.

The electronic apparatus 1 may include the interface 11. The interface11 may include a wired interface 12. The wired interface 12 may includea connector or port to which an antenna for receiving a broadcast signalbased on broadcasting standards for terrestrial/satellite broadcasting,etc. is connected or to which a cable for receiving a broadcast signalbased on cable broadcasting standards is connected. Alternatively, theelectronic apparatus 1 may include a built-in antenna to receive abroadcast signal. The wired interface 12 may include a high definitionmultimedia interface (HDMI) port, a DisplayPort, a DVI port, and thelike connector or port based on video and/or audio transmissionstandards such as thunderbolt, composite video, component video, supervideo, Syndicat des Constructeurs d'Appareils Radiorécepteurs etTéléviseurs (SCART), etc. The wired interface 12 may include a connectoror port, etc. based on universal data transmission standards such as auniversal serial bus (USB) port. The wired interface 12 may include aconnector or port, etc. to which an optical cable based on opticaltransmission standards is connected. The wired interface 12 may includea connector or port, etc. which connects with an external microphone oran external audio device including a microphone, and receives an audiosignal from the audio device. The wired interface 12 may include aconnector or port, etc. which connects with an audio device such as aheadset, an earphone, an external loudspeaker, etc. and transmits oroutputs an audio signal to the audio device. The wired interface 12 mayinclude a connector or port based on Ethernet or the like networktransmission standards. For example, the wired interface 12 may beembodied by a local area network (LAN) card or the like connected to arouter or gateway by a wire.

The wired interface 12 is connected to a set-top box, an optical mediaplayer or the like external device, a loudspeaker, a server, etc. in amanner of 1:1 or 1:N (where, N is a natural number) through theforegoing connectors or ports by a wire, thereby receiving a video/audiosignal from the connected external device or transmitting a video/audiosignal to the connected external device. The wired interface 12 mayinclude connectors or ports to transmit the video/audio signalsindividually.

Further, according to this embodiment, the wired interface 12 may beinternally provided in the electronic apparatus 1, or may be detachablyconnected to the connector of the electronic apparatus 1 as provided inthe form of a dongle or module.

The interface 11 may include a wireless interface 13. The wirelessinterface 13 may be variously embodied corresponding to the electronicapparatus 1. For example, the wireless interface 13 may use wirelesscommunication methods such as radio frequency (RF), Zigbee, Bluetooth,Wi-Fi, ultra wideband (UWB), near field communication (NFC), etc. Thewireless interface 13 may be embodied by a wireless communication modulebased on Wi-Fi, a wireless communication module for Bluetooth or thelike one-to-one direct wireless communication. The wireless interface 13performs wireless communication with a server on a network, therebyexchanging a data packet with at least one server 3. The wirelessinterface 13 may include an infrared (IR) transmitter and/or an IRreceiver to transmit and/or receive an IR signal based on IRcommunication standards. The through the IR transmitter and/or the IRreceiver, the wireless interface 13 may receive or input therein aremote control signal from the remote controller 2 or another externaldevice, or transmit or output the remote control signal to the remotecontroller 2 or another external device. Alternatively, the electronicapparatus 1 may exchange the remote control signal with the remotecontroller 2 or other external devices through the wireless interface 13of different standards such as Wi-Fi, Bluetooth, etc.

When the video/audio signal received through the interface 11 is abroadcast signal, the electronic apparatus 1 may further include a tunerto be tuned to a channel for the received broadcast signal.

The electronic apparatus 1 includes a display 14. The display 14includes a display panel capable of displaying an image on a screen. Thedisplay panel is provided to have a light receiving structure such as aliquid crystal type, or a self-emissive structure such as an organiclight emitting diode (OLED) type. The display 14 may include anadditional element according to the structures of the display panel. Forexample, when the display panel is the liquid crystal type, the display14 includes a liquid crystal display panel, a backlight unit configuredto emit light, and a panel driving substrate configured to drive liquidcrystal of the liquid crystal display panel. However, the display 14 maybe omitted when the electronic apparatus 1 is embodied by the set-topbox or the like.

The electronic apparatus 1 includes a user input unit 15. The user inputunit 15 includes circuitry related to various input interfaces providedto be controlled by a user to make a user input. The user input unit 15may be variously configured according to the kinds of electronicapparatus 1, and may for example include a mechanical or electronicalbutton of the electronic apparatus 1, a touch pad, a touch screeninstalled in the display 14, etc.

The electronic apparatus 1 includes a storage unit 16. The storage unit16 is configured to store digitalized data. The storage unit 16 includesa nonvolatile storage in which data is retained regardless of whetherpower is on or off, and a volatile memory into which data to beprocessed by the processor 2 is loaded and in which data is retainedonly when power is on. The storage includes a flash memory, a hard-discdrive (HDD), a solid-state drive (SSD), a read only memory (ROM), etc.,and the memory includes a buffer, a random-access memory (RAM), etc.When voice assistance is embodied by an application or the likesoftware, the storage unit 16 may include the voice assistance.

The electronic apparatus 1 includes the microphone 17. The microphone 17collects noise, sound, etc. of external environments, such as the userutterance 5 of the user 4. The microphone 17 transmits a collected voicesignal to the processor 6. The microphone 17 may be provided in the mainbody of the electronic apparatus 1 or in the remote controller 2, thesmartphone, etc. separated from the main body of the electronicapparatus 1. For example, the audio signal collected through themicrophone 17 provided in the remote controller 2, the smartphone, etc.may be digitalized and received in the interface 11.

Meanwhile, the smartphone or the like may be installed with aremote-control application. The smartphone or the like may function asthe remote controller through the installed application, for example,control the electronic apparatus 1, perform the voice recognitionprocess with regard to the voice signal received through the microphone17 provided in the smartphone or the like, etc. Such a remote-controlapplication may be installed in various external apparatuses such as anAI speaker, an AI robot, etc.

The electronic apparatus 1 includes a loudspeaker 18. The loudspeaker 18may output various sounds based on an audio signal. The loudspeaker 18may be embodied by at least one loudspeaker. The loudspeaker 18 may beprovided in the electronic apparatus 1, or may be embodied by anexternal loudspeaker provided in the outside. In this case, theelectronic apparatus 1 may transmit an audio signal to the externalloudspeaker by a wire or wirelessly.

The electronic apparatus 1 includes the processor 6. The processor 6includes one or more hardware processors embodied as a centralprocessing unit (CPU), a chipset, a buffer, a circuit, etc. which aremounted onto a printed circuit board, and may be embodied as a system onchip (SoC). When the electronic apparatus 1 is embodied as a displayapparatus, the processor 6 includes modules corresponding to variousprocesses, such as a demultiplexer, a decoder, a scaler, an audiodigital signal processor (DSP), an amplifier, etc. Here, some or all ofsuch modules may be embodied as an SOC. For example, the demultiplexer,the decoder, the scaler and the like video processing modules may beembodied as a video processing SOC, and the audio DSP may be embodied asa chipset separately from the SOC.

In particular, the processor 6 obtains a first character stringincluding a previously defined character from first user utterancereceived through the microphone 17, recognizes a second characterstring, which is edited from the first character string by a firstedition command, as an input character when the first edition commandfollowing the first character string is involved in the first userutterance, and performs edition with regard to a second character stringbased on a second edition command when second user utterance excludingthe first edition command includes the second edition command.

However, the configuration of the electronic apparatus 1 is not limitedto that shown in FIG. 2, but may exclude some elements from theforegoing elements or may include other elements in addition to theforegoing elements. For example, the electronic apparatus 1 includes asensor unit. The sensor unit may include at least one sensor fordetecting the motion, position, etc. of the user 4. For example, thesensor unit includes a distance sensor to detect the motion, position,etc. of the user 4 with respect to the electronic apparatus 1. Thedistance sensor may for example radiate infrared rays, ultrasonic waves,etc., and measure the motion, position, etc. of the user 4 based ondifference between time when the infrared rays, ultrasonic waves, etc.are radiated and time when the infrared rays, ultrasonic waves, etc.reflected from the user 4 or the like come back to the distance sensor.However, the sensor unit is not limited to this example, but may furtherinclude an image acquirer to capture or photograph a front side of theelectronic apparatus 1, and detect the motion, position, etc. of theuser 4 based on an image obtained through the image acquirer. The imageacquirer may be embodied by at least one camera.

Meanwhile, the processor 6 of the electronic apparatus 1 may use atleast one of a machine learning, neural network, or deep learningalgorithm as a rule-base or artificial intelligence (AI) algorithm toperform at least one of data analysis, process or result informationgeneration for the foregoing operations of obtaining the first characterstring including the previously defined character from the first userutterance, recognizing the second character string, which is edited fromthe first character string by the first edition command, as the inputcharacter when the first edition command following the first characterstring is involved in the first user utterance, and performing theedition with regard to a second character string based on the secondedition command when the second user utterance excluding the firstedition command includes the second edition command.

For example, the processor 6 may function as both a learner and arecognizer. The learner may perform a function of generating the learnedneural network, and the recognizer may perform a function of recognizing(or inferring, predicting, estimating and identifying) the data based onthe learned neural network. The learner may generate or update theneural network. The learner may obtain learning data to generate theneural network. For example, the learner may obtain the learning datafrom the storage unit 16 or server storage unit 42 or from the outside.The learning data may be data used for learning the neural network, andthe data subjected to the foregoing operations may be used as thelearning data to teach the neural network.

Before teaching the neural network based on the learning data, thelearner may perform a preprocessing operation with regard to theobtained learning data or select data to be used in learning among aplurality of pieces of the learning data. For example, the learner mayprocess the learning data to have a preset format, apply filtering tothe learning data, or process the learning data to be suitable for thelearning by adding/removing noise to/from the learning data. The learnermay use the preprocessed learning data for generating the neural networkset to perform the operations.

The learned neural network may include a plurality of neural networks(or layers). The nodes of the plurality of neural networks have weights,and the plurality of neural networks may be connected to one another sothat an output value of a certain neural network can be used as an inputvalue of another neural network. As an example of the neural network,there are a convolutional neural network (CNN), a deep neural network(DNN), a recurrent neural network (RNN), a restricted Boltzmann machine(RBM), a deep belief network (DBN), a bidirectional recurrent deepneural network (BRDNN) and deep Q-networks.

Meanwhile, the recognizer may obtain target data to perform theforegoing operations. The target data may be obtained from the storageunit 16 or the server storage unit 42, or from the outside. The targetdata may be data targeted for recognition of the neural network. Beforeapplying the target data to the learned neural network, the recognizermay preprocess the obtained target data or select data to be used in therecognition among a plurality of pieces of target data. For example, therecognizer may process the target data to have a preset format, applyfiltering to the target data, or add/remove noise to/from the targetdata, thereby processing the target data into data suitable forrecognition. The recognizer applies the preprocessed target data to theneural network, thereby obtaining an output value output from the neuralnetwork. The recognizer may obtain a probability value or a reliabilityvalue together with the output value.

FIG. 3 illustrates a control method of the electronic apparatus ofFIG. 1. Operations of FIG. 3 may be carried out by the processor 6 ofthe electronic apparatus 1. As shown in FIG. 3, the processor 6 mayobtain the first character string including the previously definedcharacter from the first user utterance (S31). Here, the previouslydefined character may be given in units of individual letters, andinclude regional characters such as a Hangeul which is Korean alphabet,an alphabet, a hiragana which is a Japanese alphabet, etc.; digits suchas ‘1’, 2’, ‘3’, etc.; and symbols such as an exclamation mark, aquestion mark, etc. However, the previously defined character is notlimited to these, but may include currencies, figures, emoticons, etc.

Further, when the first edition command subsequent to the firstcharacter string is included in the first user utterance, the processor6 may recognize the second character string, which is edited from thefirst character string by the first edition command, as the inputcharacter (S32). Here, the first edition command may include “delete” orthe like edition command. For example, “delete” may be the editioncommand issued to delete the character of the first character string.However, the kind of the first edition command is not limited to thisexample, but may be designed to include various edition commands.

Further, when the second user utterance excluding the first editioncommand includes the second edition command, the processor 6 performsedition with regard to the second character string based on the secondedition command (S33). Here, the second edition command does not includethe first edition command but may include an edition commandrecognizable as a whole or a part of the second user utterance. Forexample, when the second user utterance is “move the cursor left”, thesecond user utterance does not include the first edition command but mayinclude an edition command as a whole, which is issued to move thecursor 1 step left from a predetermined position in the previouslyobtained character string. In this case, the processor 6 may perform theedition based on the second edition command, for example, issued to makethe position of the cursor displayed on the screen be moved 1 step left.

By the control method according to this embodiment, the processor 6performs the edition based on whether or not the user utterance includesthe first edition command and the second edition command, so that morevarious and extensive edition commands can be issued, thereby improvingutilization of the edition function based on the voice recognition.

FIG. 4 illustrates a configuration of an electronic apparatus accordingto an embodiment of the disclosure. As shown in FIG. 4, the electronicapparatus 1 may include the processor 6. Below, elements of theprocessor 6 according to this embodiment and operations of the elementswill be described in detail.

The processor 6 may include a feature extractor 41. The featureextractor 41 may extract a feature vector from received user utterance.The feature extractor 41 may use various algorithms to extract thefeature vector.

The processor 6 may include a voice recognizer 42. The voice recognizer42 may recognize a character string from the feature vector of the userutterance extracted by the feature extractor 41, and generate or outputthe recognized character string. The voice recognizer 42 may recognizethe previously defined character included in the character string inunits of spacing words. The voice recognizer 42 may output recognitionresults including spacing in relation to the previously definedcharacter, and output recognition results including spacing conformingto a word spacing rule with regard to a word. For example, the voicerecognizer 42 may output a character string of “a b c” with regard touser utterance of “a b c”.

The processor 6 may include a first intention analyzer 43. The firstintention analyzer 43 may perform a first intention analysis, in otherwords, may analyze intention of the user 4 with regard to the characterstring recognized by the voice recognizer 42. To analyze the intentionof the user 4 in real time with regard to the character string, which isgiven in units of spacing words, output in the middle of the userutterance, the first intention analyzer 43 may for example recognize thefirst edition command such as “delete”, “delete all”, “cancel”, etc.“Delete” refers to an edition command intended to delete a character ofthe character string, and “delete all” refers to an edition commandintended to delete all the character string. Further, “cancel” refers toan edition command intended to cancel an input to the previously inputcharacter.

The first intention analyzer 43 may analyze intention for the characterstring in real time, by recognizing the first edition command of whichthe kinds or numbers and levels are restricted as described above.Meanwhile, the first edition command is contrasted with the secondedition command to be recognized by a second intention analyzer 45 to bedescribed later, in which the second edition command is recognized as awhole or a part of the character string and thus different from thefirst edition command in being recognized with more kinds or numbers andmore extensive levels.

To analyze the intention of the user 4, the first intention analyzer 43may ignore the character strings except the previously defined characterand the first edition command in the user utterance. For example, whenthe user utterance is “a b c delete please”, the first intentionanalyzer 43 ignores the character string of “please” even though “pleasedelete a b c” contains a predetermined character string of “please” inaddition to the character string of “a b c” including previously definedcharacters and the first edition command of “delete”, thereby analyzingthe intention of the user 4 for deleting “c” from the character stringof “a b c” based on the user utterance.

The processor 6 may include a character string editor 44. The characterstring editor 44 may edit the character string based on the firstintention analysis of the first intention analyzer 43, in other words,intention of a user 4 analyzed by the first intention analyzer 43.Below, it will be described in detail that the character string editor44 edits the character string based on the first intention analysis, forexample, when the user utterance is “1 2 3 delete 4 5 delete all 7 8.”Based on the user utterance of “1 2 3 delete”, “123” is displayed on thecharacter input screen, but “delete” deletes “3” from “1 2 3” displayedon the character input screen, thereby causing only “1 2” to bedisplayed. Then, the user utterance of “4 5” causes “1 2 4 5” to bedisplayed on the character input screen, and the following userutterance of “delete all” causes “1 2 4 5” displayed on the characterinput screen to be deleted. Therefore, any character is not displayed onthe character input screen. In addition, the user utterance of “7 8”causes “7 8” to be newly displayed on the character input screen. Inother words, the character string editor 44 can obtain the characterstring of “7 8” based on the intention of the user 4 contained in theuser utterance of “1 2 3 delete 4 5 delete all 7 8.”

Below, it will be described in detail that the second intention analyzer45 performs the second intention analysis with regard to the userutterance, in other words, additionally analyzes the intention of theuser 4, and performs the edition with regard to the previously obtainedcharacter string based on the analyzed intention. However, when thecharacter string is edited based on the first edition command identifiedby the first intention analyzer 43, an additional intention analysis oredition of the second intention analyzer 45 may be designed not to becarried out.

The processor 6 may further include the second intention analyzer 45.The second intention analyzer 45 may recognize the user utterance forcontrolling general functions of the electronic apparatus 1. Forexample, the second intention analyzer 45 may recognize whether acharacter string obtained from user utterance by the feature extractor41 and the voice recognizer 42 contains a function control command suchas volume control, channel switching, etc. in the TV, and make theelectronic apparatus 1 operate based on the recognized function controlcommand. In other words, the second intention analyzer 45 may controlthe function of the electronic apparatus 1 based on a recognized controlcommand when the user utterance is recognized as a general functioncontrol command, and may perform the edition based on a recognizedsecond edition command when the user utterance is recognized ascontaining the second edition command to be described later in detail.

After the user utterance is finished, the second intention analyzer 45may apply the second intention analysis to each or all of the wholecharacter string recognized by the voice recognizer 42 and the characterstring primarily edited by the character string editor 44 based on thefirst intention analysis. The second intention analysis refers toanalysis of whether each character string contains the second editioncommand. For example, when the user utterance is “move the cursor 3steps left”, the second intention analyzer 45 may identify that thecharacter string of “move the cursor 3 steps left” recognized by thevoice recognizer 42 contains the second edition command issued to movethe cursor displayed on the character input screen 3 steps left, andmake the position of the cursor displayed on the character input screenbe moved 3 steps left based on the identified second edition command.

According to the foregoing first intention analysis, the characterstrings except the previously defined character and the first editioncommand are ignored in the character string of “move the cursor 3 stepsleft” recognized by the voice recognizer 42, and therefore the characterstring primarily edited based on the first intention analysis may be“3”. On the other hand, the second intention analyzer 45 may identifythat the second edition command is not included in the character stringof “3” as a result of applying the second intention analysis to thecharacter string of “3”, thereby performing the edition based on thesecond edition command identified as included in the whole characterstring of “move the cursor 3 steps left” while ignoring the result ofthe second intention analysis to the character string of “3”. However,the edition is not limited to that performed by the second intentionanalyzer 45. As necessary, the edition may be performed by the characterstring editor 44 based on the second edition command identified by thesecond intention analyzer 45.

On the other hand, when it is identified as the result of the secondintention analysis that the second edition command is not includedthroughout the whole character string, the second intention analyzer 45may recognize the primarily edited character string as the inputcharacter. Referring to the foregoing example, when the character stringrecognized by the voice recognizer 42 is “1 2 3 delete 4 5 delete all 78” but the character string edited by the character string editor 44 is“7 8”, the second intention analyzer 45 may identify that the secondedition command is not included in the character string of “1 2 3 delete4 5 delete all 7 8” and identify the primarily edited character stringof “7 8” as the input character.

Like this, the processor 6 according to an embodiment fulfils thecharacter input more appropriate to suite the utterance intention of theuser 4 by applying the first intention analysis and the second intentionanalysis to the user utterance, thereby improving reliability of thecharacter input based on the voice recognition.

FIG. 5 shows another example of the control method of the electronicapparatus shown in FIGS. 3 and 4. Operations shown in FIG. 5 are givento more specify the operations of FIG. 3, and the following detaileddescriptions will be made focusing on parts not described with referenceto FIG. 3. As shown in FIG. 5, the processor 6 may obtain a characterstring from user utterance (S51).

Further, the processor 6 may perform the first intention analysis, inother words, identify whether the obtained character string contains thefirst edition command (S52).

When the obtained character string includes the first edition command,the processor 6 may edit the character string based on the first editioncommand (S53).

Further, the processor 6 may perform the second intention analysis, inother words, identify whether the character string edited based on thefirst edition command includes the second edition command (S54). When itis identified in the operation S53 that the first edition command is notincluded in the obtained character string, the processor 6 may apply thesecond intention analysis to the obtained character string, in otherwords, identify whether the second edition command is included in theobtained character string.

When it is identified that the edited character string or obtainedcharacter string contains the second edition command, the processor 6may edit the character string based on the identified second editioncommand (S55).

Thus, by the control method according to an embodiment, the processor 6applies two-step intention analyses to the user utterance, and thusfulfils the character input more appropriate to suite the utteranceintention of the user 4, thereby improving reliability of the characterinput based on the voice recognition.

FIG. 6 shows an example of a user input for activating a character inputmode in connection with the operation S51 in FIG. 5. As shown in FIG. 6,the processor 6 may activate a character input mode to receive userutterance for a character input.

The processor 6 may activate the character input mode by a previouslydefined event for starting the character input mode. The previouslydefined event for starting the character input mode may include a userinput for starting the character input mode, for example, selection of avoice input button, reception of a starting trigger, etc. The startingtrigger may include “character input start” or the like preset voicecommand which means the activation of the character input mode. Thevoice input button may be provided in the main body of the electronicapparatus 1, but not limited thereto. Alternatively, the voice inputbutton may be provided in the remote controller 2, the smartphone, etc.Further, the microphone 17 for receiving the starting trigger may beprovided in not only the main body of the electronic apparatus 1 butalso the remote controller 2, the smartphone, etc. In this case, theprocessor 6 may receive a voice signal corresponding to the startingtrigger from the remote controller 2, the smartphone, etc. However, thepreviously defined event for starting the character input mode is notlimited to the foregoing description, but may be variously designed.

Further, the processor 6 may terminate the activation of the characterinput mode based on an event previously defined for terminating thecharacter input mode, in other words, inactivate the character inputmode. The event previously defined for terminating the character inputmode may include selection release of the voice input button forstarting the character input mode, reception of a termination triggerfor terminating the character input mode, etc. The termination triggermay include “character input end” or the like preset voice command whichmeans the inactivation of the character input mode. However, thepreviously defined event for terminating the character input mode is notlimited to the foregoing description. Alternatively, the processor 6 mayterminate the activation of the character input mode based on whether apredetermined period of time elapses. For example, when a predeterminedperiod of time elapses after a user input for starting the characterinput mode, for example, selection of the voice input button, receptionof the starting trigger, etc. or when a predetermined period of timeelapses after receiving the first user utterance during the activationof the character input mode, the processor 6 may identify as thepreviously defined event for terminating the character input mode.

Thus, the processor 6 according to an embodiment can activate orinactivate the character input mode based on variously defined events,thereby improving convenience in the character input based on the voicerecognition.

FIG. 7 shows an example of performing the first intention analysisduring the activation of the character input mode in connection with theoperation S52 in FIG. 5. As shown in FIG. 7, the processor 6 may receivethe user utterance while the character input mode is being activated.

The processor 6 may perform the first intention analysis with regard touser utterance while the character input mode is being activated. Inother words, the processor 6 may recognize the first edition commandsubsequent to the character string obtained from the user utteranceduring the activation of the first character input mode, and edit thecharacter string based on the recognized first edition command.

When the activation of the character input mode is terminated withregard to the user utterance, the processor 6 may perform the secondintention analysis. In other words, when the activation of the characterinput mode is terminated, the processor 6 may identify whether thesecond edition command is contained in the user utterance which does notinclude the first edition command, and edit the character string basedon the identified second edition command.

Like this, the processor 6 according to an embodiment performs thesecond intention analysis after the activation of the character inputmode is terminated with regard to the user utterance received during theactivation of the character input mode, and thus fulfils the characterinput more appropriate to suite the utterance intention of the user 4,thereby improving reliability of the character input based on the voicerecognition.

FIG. 8 shows an example of a control method of inputting a character inconnection with the operations S32 and S33 in FIG. 3. Below, a method ofinputting a character based on the intention analysis according to anembodiment will be described in detail with reference to FIG. 8 togetherwith FIG. 9.

The processor 6 may recognize a text from the user utterance (S81). Forexample, as shown in FIG. 9, it will be assumed that the character inputscreen, e.g. a password input screen 92 is displayed, and characters ina password are input based on user utterance. In this case, when userutterance 91 of “1245 delete” is received from the user 4, the processor6 may recognize a text of “1245 delete” from the user utterance 91.

When the recognized text contains the previously defined character, theprocessor 6 may obtain the first character string in which thepreviously defined character is contained (S82). For example, the textof “1245 delete” contains the previously defined character of “1245”,and therefore the processor 6 can obtain the first character string of“1245” including the previously defined character “1245”.

Further, when the first edition command following the first characterstring is contained in the text, the processor 6 may obtain the secondcharacter string edited from the first character string based on thefirst edition command (S83). For example, the processor 6 may identifythat the text of “1245 delete” contains the first edition command“delete” following the first character string of “1245”, and thus obtainthe second character string of “124” edited from the first characterstring of “1245” based on the first edition command of “delete”.

Further, when the text does not include the second edition command, theprocessor 6 may recognize the second character string as the inputcharacter (S84). For example, the second edition command is notcontained in the text of “1245 delete”, and therefore the processor 6recognizes the second character string of “124” as the input character,thereby for example displaying a password of “123” on the password inputscreen 92.

FIG. 10 shows an example of a control method of inputting a character inconnection with the operations S32 and S33 in FIG. 3. Below, a method ofinputting a character based on the intention analysis according to anembodiment will be described in detail with reference to FIG. 10together with FIG. 11.

The processor 6 may recognize a text from user utterance (S101). Forexample, as shown in FIG. 11, it will be assumed that user utterance 110of “move the cursor 2 steps left” is received with regard to the secondcharacter string of “124” described with reference to FIG. 9. In thiscase, the processor 6 may obtain a text of “move the cursor 2 stepsleft” from the user utterance 110 of “move the cursor 2 steps left”.

Further, when the text contains the previously defined character butdoes not contain the first edition command following the first characterstring including the previously defined character, the processor 6 mayidentify whether the text contains the second edition command (S102).For example, when the previously defined character of “2” is containedin the text of “move the cursor 2 steps left”, the processor 6 mayobtain a third character string of “2”. However, when the first editioncommand subsequent to the third character string of “2” is notcontained, the processor 6 may identify whether the second editioncommand is contained in the text of “move the cursor 2 steps left”.

Further, when it is identified that the text contains the second editioncommand, the processor 6 may perform edition with respect to the firstcharacter string based on the identified second edition command (S103).For example, when it is identified that the text of “move the cursor 2steps left” contains the second edition command, the processor 6 mayperform the edition based on the second edition command, for example,move the cursor, which is positioned behind “4” in the second characterstring of “124” input as the password on the password input screen 92, 2steps left to be positioned in between “1” and “2”.

When the text does not contain the second edition command, the processor6 may recognize the previously obtained third character string of “2” asthe input character. In other words, when the text contains the secondedition command even though it contains the previously definedcharacter, the processor 6 may preferentially perform the edition basedon the second edition command.

FIG. 12 shows an example of a control method of inputting a character inconnection with the operations S32 and S33 in FIG. 3. Below, a method ofinputting a character based on the intention analysis according to anembodiment will be described in detail with reference to FIG. 12together with FIG. 13.

The processor 6 may recognize a text from user utterance (S121). Forexample, as shown in FIG. 13, a text of “move the cursor left” may beobtained from user utterance 130 of “move the cursor left”.

Further, when the text does not contain the previously defined characterand the first edition command, the processor 6 may identify whether thetext contains the second edition command (S122). For example, both thepreviously defined character and the first edition command are notcontained in the text of “move the cursor left”, and therefore theprocessor 6 may identify whether the text of “move the cursor left”contains the second edition command.

Further, when it is identified that the text contains the second editioncommand, the processor 6 may perform edition with respect to thepreviously obtained character string based on the identified secondedition command (S123). For example, when it is identified that the textof “move the cursor left” contains the second edition command, theprocessor 6 may perform the edition based on the second edition command,for example, move the cursor, which is positioned behind “4” in thesecond character string of “124” input as the password on the passwordinput screen 92, 1 step left to be positioned in between “2” and “4”.

FIG. 14 shows an example of a control method of inputting a character inconnection with the operations S32 and S33 in FIG. 3. Below, a method ofinputting a character based on the intention analysis according to anembodiment will be described in detail with reference to FIG. 14together with FIG. 15.

The processor 6 may recognize a text from user utterance (S141). Forexample, as shown in FIG. 15, when user utterance 150 of “3” is receivedin the state that a cursor 7 is positioned between “2” and “4” in thesecond character string of “124”, the processor 6 may recognize a textof “3” from the user utterance 150 of “3”.

Further, when the text contains the previously defined character, theprocessor 6 may obtain the first character string containing thepreviously defined character (S142). For example, the processor 6 mayobtain a fourth character string of “3” containing the previouslydefined character “3” from the text of “3”.

Further, when the text does not contain the first edition commandfollowing the first character string and also does not contain thesecond edition command, the processor 6 may recognize the firstcharacter string as the input character (S143). For example, theprocessor 6 may recognize the fourth character string of “3” as theinput character because the text of “3” does not contain the firstedition command subsequent to the fourth character string of “3” and thetext of “3” does not contain the second edition command. The processor 6may for example display “3” in between “2” and “4” of the secondcharacter string of “124” displayed on the password input screen.

FIG. 16 shows an example of a first voice recognition engine and asecond voice recognition engine used by the processor of FIG. 4. Asshown in FIG. 16, the processor 6 may perform voice recognition based ona voice recognition engine 160. The voice recognition engine 160 mayinclude a first voice recognition engine 161 for the first intentionanalysis, and a second voice recognition engine 162 for a secondintention analysis.

In other words, when user utterance is received to input a characterbased on voice recognition, the processor 6 may perform the firstintention analysis with regard to the user utterance based on the firstvoice recognition engine 161. For example, the processor 6 may recognizethe first edition command, e.g. “delete”, “delete all”, etc. containedin the user utterance based on the first voice recognition engine 161.

Further, the processor 6 may recognize that the user utterance containsthe second edition command based on the second voice recognition engine162. Here, the kind or number of edition commands recognizable asincluding the second edition command based on the second voicerecognition engine 162 may be more than the kind or number of editioncommands recognizable as including the first edition command based onthe first voice recognition engine 161. Further, an edition level of thesecond edition command may be higher in quality than the edition levelof the first edition command based on the first voice recognition engine161.

Meanwhile, the processor 6 may recognize the user utterance forcontrolling general functions of the electronic apparatus 1 based on thesecond voice recognition engine 162. For example, the processor 6 mayrecognize user utterance for requesting specific content, e.g. a populardrama, a good scene of a baseball game, etc. as well as the userutterance for volume control, channel switching, etc. of the TV based onthe second voice recognition engine 162.

In other words, the processor 6 may perform the edition based on anidentified second edition command when the second voice recognitionengine 162 identifies that the user utterance contains the secondedition command, and also control the functions of the electronicapparatus 1 based on a recognized control command when the userutterance is recognized as a general function control command.

Thus, the processor 6 according to an embodiment may use a single voicerecognition engine to perform the edition for the character string orcontrol general functions, thereby efficiently managing resources forthe voice recognition.

Various embodiments of the disclosure may be achieved by softwareincluding one or more commands stored in a storage medium readable bythe electronic apparatus 1 and the like. For example, the processor 6 ofthe electronic apparatus 1 may call and execute at least one commandamong one or more stored commands from the storage medium. This enablesthe electronic apparatus 1 and the like apparatus to operate and performat least one function based on the at least one called command. The oneor more commands may include a code produced by a compiler or a codeexecutable by an interpreter. The machine-readable storage medium may beprovided in the form of a non-transitory storage medium. Here, the‘non-transitory’ merely means that the storage medium is a tangibledevice and does not include a signal (for example, an electromagneticwave), and this term does not distinguish between cases of beingsemi-permanently and temporarily stored in the storage medium. Forexample, the ‘non-transitory’ storage medium may include a buffer inwhich data is temporarily stored.

For example, methods according to various embodiments of the disclosuremay be provided as involved in a computer program product. The computerprogram product according to the disclosure may include instructions ofsoftware to be executed by the processor as mentioned above. Thecomputer program product may be traded as a commodity between a sellerand a buyer. The computer program product may be distributed in the formof a machine-readable storage medium (for example, a compact disc readonly memory (CD-ROM)) or may be directly or online distributed (forexample, downloaded or uploaded) between two user apparatuses (forexample, smartphones) through an application store (for example, PlayStore™). In the case of the online distribution, at least a part of thecomputer program product (e.g. a downloadable app) may be transitorilystored or temporarily produced in a machine-readable storage medium suchas a memory of a manufacturer server, an application-store server, or arelay server.

According to the disclosure, there are provided an electronic apparatusand a control method thereof, in which more various and extensiveedition commands can be issued for a wrong character input during acharacter input using a voice recognition function, thereby improvingutilization of an edition function based on voice recognition.

Although a few embodiments have been shown and described, it will beappreciated by those skilled in the art that changes may be made inthese embodiments without departing from the principles and spirit ofthe invention, the scope of which is defined in the appended claims andtheir equivalents.

What is claimed is:
 1. An electronic apparatus comprising: a memory; aprocessor, coupled to the memory, and configured to: obtain a firstcharacter string including a predetermined character from a first voiceinput; based on the first voice input including a first commandfollowing the first character string, perform a function correspondingto the first command for changing the first character string, andidentify the changed first character string to be a second characterstring that is an input character; and based on a second command beingincluded in a second voice input without the first command, perform afunction corresponding to the second command for changing the secondcharacter string.
 2. The electronic apparatus according to claim 1,wherein the first command includes a command to delete a characterincluded in the first character string.
 3. The electronic apparatusaccording to claim 1, wherein the first command is one of a firstplurality of recognizable commands and the second command is one of asecond plurality of recognizable commands, the second plurality ofrecognizable commands being more than the first plurality ofrecognizable commands.
 4. The electronic apparatus according to claim 1,wherein the processor is configured to: identify the second commandbased on a voice recognition engine; and identify a command forcontrolling the electronic apparatus based on the voice recognitionengine.
 5. The electronic apparatus according to claim 1, wherein theprocessor is configured to identify the first character string and thefirst command with regard to the first voice input received in acharacter input mode activated based on a predetermined event.
 6. Theelectronic apparatus according to claim 5, wherein the processor isconfigured to identify whether the second command is included in thesecond voice input received while the character input mode is beingactivated.
 7. The electronic apparatus according to claim 5, wherein theprocessor is configured to: activate the character input mode based on afirst event; and terminate the activation of the character input modebased on a second event.
 8. The electronic apparatus according to claim5, wherein the processor is configured to activate the character inputmode based on a received user input.
 9. The electronic apparatusaccording to claim 1, wherein, when the processor obtains a thirdcharacter string including the predetermined character from the secondvoice input, the processor is configured to perform the functioncorresponding to the second command for changing the second characterstring without identifying the third character string as the inputcharacter.
 10. The electronic apparatus according to claim 9, furthercomprising a display, wherein the processor is configured to control thedisplay to display the second character string identified as the inputcharacter but not to display the third character string not identifiedas the input character.
 11. The electronic apparatus according to claim1, wherein the processor is configured to: obtain a fourth characterstring including the predetermined character from a third voice input;and based on the third voice input without the first command followingthe fourth character string, identify the fourth character string as theinput character.
 12. The electronic apparatus according to claim 1,wherein the processor is configured not to identify whether the secondvoice input includes the second command, based on the first voice inputincluding the first command.
 13. A method of controlling an electronicapparatus, comprising: obtaining a first character string including apredetermined character from a first voice input; based on the firstvoice input including a first command following the first characterstring, performing a function corresponding to the first command forchanging the first character string, and identifying the changed firstcharacter string to be a second character string that is an inputcharacter; and based on a second command being included in a secondvoice input without the first command, performing a functioncorresponding to the second command for changing the second characterstring.
 14. The method according to claim 13, wherein the first commandincludes a command to delete a character included in the first characterstring.
 15. The method according to claim 13, wherein the first commandis one of a first plurality of recognizable commands and the secondcommand is one of a second plurality of recognizable commands, thesecond plurality of recognizable commands being more than the firstplurality of commands.
 16. The method according to claim 13, wherein theperforming the function corresponding to the second command comprises:identifying the second command based on a voice recognition engine; andidentifying a command for controlling the electronic apparatus based onthe voice recognition engine.
 17. The method according to claim 13,wherein the obtaining the first character string comprises identifyingthe first character string and the first command with regard to thefirst voice input received in a character input mode activated based ona predetermined event.
 18. The method according to claim 17, wherein theperforming the function corresponding to the second command comprisesidentifying whether the second command is included in the second voiceinput received while the character input mode is being activated. 19.The method according to claim 17, further comprising: activating thecharacter input mode based on a first event; and terminating theactivation of the character input mode based on a second event.
 20. Anon-transitory recording medium stored with a computer programcomprising a code for performing a control method of an electronicapparatus as a computer readable code, the control method comprising:obtaining a first character string including a predetermined characterfrom a first voice input; based on the first voice input including afirst command following the first character string, performing afunction corresponding to the first command for changing the firstcharacter string, and identifying the changed first character string tobe a second character string that is an input character; and based on asecond command being included in a second voice input without the firstcommand, performing a function corresponding to the second command forchanging the second character string.